1. Flandrian Sedimentation and Palaeoenvironments in Pett Level, the Brede and Lower Rother Valleys and Walland Marsh

Martyn Waller, Paul J. Burrin and Andrew Marlow

Introduction work has now been extended into the lower Brede. In the Romney Marsh is one of the largest areas of reclaimed Rother valley, subsurface investigations have extended marshland in Britain. Despite its size, little is known from the fluviatile sequences (see Burrin 1988) to the about the sedimentary sequences of which it is deposits of the lower Rother, the Rother Levels and out comprised. Early investigations of the marshlands have across Walland Marsh to the Rhee Wall. All these now largely been superseded, a notable exception being investigations have been concerned with the identific- the work on the formation of the shingle barrier at ation and correlation of the sedimentary sequences Dungeness (Gulliver 1897; Lewis 1932; Lewis and found, and the reconstruction of depositional environ- Balchin 1940). Recent attempts to reconstruct the ments. Here a preliminary attempt is made to integrate formation of the marshland (Cunliffe 1980; Brooks 1981; these results in order to produce a clearer understanding Eddison 1983a, 1983b) have tended to focus on changes of the development of the western tracts of the occurring during the historic period. Much of the marshland. However, prior to describing the results of detailed information upon which these discussions are this more recent research, it is useful to outline the ideas based originates from the work of Green ( 1968) and his of Green (further refined by Cunliffe 1980, Brooks 1981 colleagues at the Soil Survey of England and Wales and Eddison 1983a, 1983b), so that the difficulties and (Green and Askew 1958a, 1958b, 1959, 1960). Green discrepancies encountered in relation to this new (1968) was responsible for recognising the basic material can be more fully appreciated. stratigraphic sequence which is thought to characterise the marshland. Examination of the general character of the deeper deposits and a detailed study of the near The Depositional History of Romney Marsh surface sediments, together with consideration of The landward boundary of the marshland is marked by historical documentation and cartographic evidence, a prominent and now abandoned cliff-line, which is best enabled Green to advance a model of the evolution of the developed on the erosionally resistant sands of the marshlands. In spite of these studies there are still many Wealden Series (Fig. 1.2). The age, origin and uncertainties. Particularly lacking are data concerning development of the cliffs remain largely unresolved. the development of the river valleys during the evolution Kellaway et al. (1975) and Destombes et al. (1975) imply of the marshland. The lithostratigraphy, depositional that this feature may date from the preceding environment and chronology of the valley fill deposits (Ipswichian) interglacial and that it has been modified, and their inter-relationships with the marshland rather than created, by the subsequent Flandrian sequences are unknown. The primary aim of this transgression. A recent investigation of landslides at research has been to fill this significant gap in the Lympne (Hutchinson et al. 1985) has indicated that the understanding of the evolution of the Romney Marsh cliff-line here was probably abandoned by c. 5000 B.P., area. with later instability producing the current slope The investigations described in this paper are the morphology. result of a series of studies into the deposits of this area Little is also known regarding the characteristics of (Fig. 1 .l). The Flandrian vegetational history of the the deepest deposits of the marsh, for few boreholes have Brede valley is being investigated by Martyn Waller and penetrated the alluvium to bedrock. Of the five a detailed understanding of the lithostratigraphy, pollen boreholes quoted in Shephard-Thorn et al. (1966) and assemblages and plant macrofossils is emerging, Smart et al. (1966) only two appear to provide reliable supported by radiocarbon dating. Initial investigations information. These record bedrock at c. -20m in the adjacent but smaller Pannel valley were first (Langdon) and c. -28m (Guldeford Lane Corner) reported by Woodcock (1984). This work has now been respectively. Two deep boreholes in the valley alluvium complemented by analyses from a further site. The of the lower Tillingham and lower Rother also record lithostratigraphy and foraminiferal assemblages of Pett bedrock at - 24.5m O.D. (Tilling Green, Rye) and Level have been described by Marlow (1984) and this c. - 28m O.D. (Wittersham Bridge). The deepest 4 Martyn Waller, Paul J. Burrin and Andrew Marlow

......

......

THE DOWELS

TONE BRIDGE

......

A RYE BAY

......

IRLIGHT HEAD

Fig. I .l Location of sites deposits recorded in these boreholes are variable, Midley (TR 031232) (Green and Askew 1958b). This ranging from peats at Langdon and Tilling Green, of sand is relatively coarse when compared with the which the latter have been dated to 9565 * 120 B.P. marshland's younger sandy deposits. Where it occurs (Welin et al. 1974), to clays and sands with gravel close to or at the surface prominent sand ridges are elsewhere. Consequently, comments relating to the evident trending south-west to north-east. Green (1968) general morphology of the bedrock surface, or to the suggests they are part of an extensive feature, such as a composition and origins of these basal materials, rely on sand spit, or a system of sand banks or dunes, which a very restricted database and must be viewed with some suffered dissection and reworking during subsequent caution. periods. The most reliable information concerning the The Midley Sand is overlain by the Blue Clay, which marshland sediments to-date is that provided by the Soil has a high silt content and contains shells of the estuarine Survey of England and Wales (Green 1968). The bivalve Scrobicularia. Above this deposit is an extensive deepest deposit identified is the Midley Sand, so named peat bed, which is thickest in the Dowels east of because it outcrops at the surface in the vicinity of Appledore but thins to the east and wedges out Flandrian Sedimentation and Palaeoenvironments 5

......

FRESHWATER

WEALD CLAY TUNBRIDGE WELLS SAND WADHURST CLAY

Fig. 1.2 Geology of stu4 area completely over the Midley Sand deposits near Lydd was sub-divided by Green into Decalcified (Old) (Green 1968). The peat is said to contain the trunks of Marshland, where the post-peat deposits are often thin, oak and hazel, as well as alder remains (Drew 1864). and Calcareous (New) Marshland, which contain thick The original extent and thickness of the peat is likely to post-peat deposits. These more recent events in the have been altered by a number of factors including marshland's depositionary history are believed to be erosion, compaction and wastage through oxidation. closely related to the development of barrier beach Two radiocarbon dates are available from the main systems. The earliest date for the origins of such marshland peat bed: 3020f 94 B.P. at Appledore structures is uncertain. An early Flandrian age for Dowrels and 3340f 92 B.P. from h'alland Marsh barrier beaches further west along the south coast at (Callow et al. 1964). Langney Point, Eastbourne has been suggested by Subsequent deposits, referred to as the 'Young Jennings and Smyth (1982a). In Romney Marsh, Alluvium' by Green (1968), have been the subject of Eddison (1983a, 1983c) has argued that barriers may much attention and speculation in attempts to have provided a sheltered environment behind which understand the historic evolution of this area. The marsh peat accumulation could have occurred. As peat was 6 Martyn Waller, Paul 3. Burrin and Andrew Marlow forming by c. 5300 B.P. at Pett Level (Welin et al. 1972), purposes of which have been much debated. It is clearly Eddison suggested that shingle had accumulated artificial and is not a depositional boundary (except significantly by this period. Others however, including between Appledore and Snargate) which indicates that Green, have envisaged peat formation occurring during the 'wall' did not function as a seabank (Green 1968). a period of relatively low sea level. 'The earliest All recent authors agree that the Rhee Wall was a canal unequivocal evidence for barrier formation (but see built prior to 1257, when it was extended seaward to Tooley 1988) consists of a series ofshingle beaches west of scour the New Romney estuary which was becoming Lydd. These follow the SW-NE alignment of the Midley increasingly obstructed by sediment. This problem was Sand and are overlain by 'clay with roots' dated to exacerbated by the storms of this period which were 2740 f 400 B.P. and a thin peat dated to 2050 f 90 B.P. threatening the existence of New Romney as a port (Callow et al. 1966), which Green ( 1968) correlated with (Green 1968; Cunliffe 1980; Eddison 1983a, 1983b). the Blue Clay and peat respectively of the marshland. The Rhee Wall itself appears to have been threatened at The alignment of the surface outcrops of Midley Sand Appledore during this period by a marine inundation of and early shingle deposits has led to the suggestion that a Walland Marsh. Brooks (1981) has reopened earlier spit may once have extended from Fairlight to Hythe, arguments by challenging Green's (1968) view that the forming as a result of the predominantly eastward whole of this second area of calcified marshland was longshore drift (Lewis 1932; Lewis and Balchin 1940; reclaimed after the storms of the thirteenth century, as Cunliffe 1980; Eddison 1983a), this structure being the documentary evidence suggests that Denge Marsh precursor of the present-day cuspate foreland of formed part of the archepiscopal estate of Lydd as early Dungeness. as the tenth century. The deposits of the post-peat period (the Young The third tract of calcareous marshland occurs in the Alluvium) are complex and appear to relate to the vicinity ofRye and Walland Marsh. The boundary with episodic breaching of the barrier system. Green (1968) the decalcified marshland in Walland Marsh coincides identified three areas of calcareous marshland which with an important cordon of old sea walls which zigzag have thick post-peat deposits and reveal the location of for some 15 miles between Appledore and Broomhill. former estuaries associated with gaps in the shingle Green attributed these calcareous deposits to the storms barrier. Of particular significance is a large area of of the thirteenth century which led to the drowning of calcareous deposits in the north-east of the marsh which much of this area and, it was suggested, to the capture of represents an estuary with its mouth near Hythe. the Rother from New Romney. There is, however, Cunliffe (1980) correlated this phase of coastal evidence for the existence of an estuary in the Rye area development with archaeological evidence suggesting prior to the 13th century. Brooks (1981) notes the that a Roman fort near Lympne would have occupied a absence of Anglo-Saxon place names and Domesday strategic position controlling access to the eastern Weald settlements over Walland Marsh, suggesting that this if the Rother and its tributaries met the sea near Hythe. area was not settled during this period, while Eddison However, the arguments for the present-day Sedbrook (1983a) refers to the Domesday records (Darby and Sewer representing a northern channel or distributary of Campbell 1962) concerning the presence of l00 salt pans the Rother (or Limen) as suggested by Green and Askew at Rye. The existence of the port ofold Winchelsea prior (1959) remain unsubstantiated. The small scale of this to the 13th century storms also suggests the presence of feature makes such a route unlikely and it may only have an estuary in this area. The age of this estuary and the been a tidal creek feeding into the Hythe estuary associated gap in the shingle barrier therefore remain (Eddison 1983a). Shells collected from a similar creek, unknown, although this has important implications for dated to 1550 f 120 B.P. (Callow et al. 1964) are said to the development of Dungeness, in that the resultant indicate that infilling was occurring by late Roman isolation of the shingle to the west was partly responsible times (Green 1968). Brooks (1981) reviewing the for the realignment of the foreland (Lewis 1932). Most of documentary evidence suggests that this north-eastern this part of the marsh appears to have been reclaimed by area of calcareous marshland was available for the 1 7th century as illustrated in Poker's map of 16 17. settlement by the middle Saxon period. A second area of calcareous marshland and associated relic creek patterns occurs in the vicinity of New Lithostratigraphic Investigations Romney and Denge Marsh. Green (1968) detected the course of a natural waterway extending from Appledore Methods to New Romney, where it widens into this area of Information concerning the lithostratigraphy of the calcareous marshland. The origin of this channel, lower valleys and western marshland has been obtained usually referred to as the Romney branch of the Limen, from a variety ofsources. Much of the data was acquired has not been established. It does not appear to relate to by hand augering using a gouge sampler at a variety of parish boundaries which suggests (Brooks 198 1) that it locations within the specified areas. Penetration of the post dates them. Evidence for the existence of this fine-grained silts, clays and peat was generally effective, watercourse in the 8th century can be found from land although difficulties were encountered with wood charters (Ward 1940, Brooks 1981). Parallel to this remains and compacted sands. The elevation of each natural course lies the Rhee Wall, the origins and borehole relative to Ordnance Datum was surveyed in Flandrian Sedimentation and Palaeoenvironments 7

using a Kern Quickset level, heights being obtained from a widespread, intercalated blue grey (5 B 511) clay benchmark lists. (between -3.55m O.D. and -2.01m O.D.), with Additional sources of information concerning these evidence for at least two such layers in some boreholes deposits include the borehole logs held by East Sussex (Marlow 1984).The peat is largely detrital in character County Council as part of site investigation reports into and wood remains occur widely as is apparent in the plans for a Winchelsea diversion and a by-pass around outcrops which occur along the present-day littoral Rye. These records are sufficiently detailed for them to zone. On the long profile the upper contact of the peat is be included in the database, but the same is generally diffuse, although sharp boundaries occur in unfortunately not true of the county well records boreholes 1 and 2. The overlying deposits consist ofblack collated by Cole et al. (1965). The British Geological (5 Y 2.5/1), dark grey (N4/) and dark bluish grey (5 B Survey also provided additional borehole data. The 411) frequently laminated silty clays with sand, from location of the sites described in this paper are shown in - 4.52m O.D. to 1.13m O.D. This material is in turn Fig. 1.1. buried by a grey (5 YR 511) and greyish brown (10 YR 512) to brown (l0YR 413) mottled with red (2.5 YR 518) silty clay found between 0.37m O.D. and 2.35m O.D. Results

The sedimentary characteristics of Pett Level, the Brede MODIFIED FROM TROELS-SMITH (1955) valley, the lower Rother, and the Rother Levels extending out into the marshland, are described in an Components Boundaries attempt to identify and define the major stratigraphic units. Description of the organic deposits follows Troels- DISTURBED GROUND --- > lcm Smith (1955); the sediment symbols in the accompany- ing diagrams have, however, been modified from this As CLAY - lcm-lmm scheme (Fig. 1.3a). - < lmm Ag SILT Pett Level ..... UNKNOWN The augering of fifty-four boreholes on Pett Level G. FINE SAND revealed a complex sedimentary sequence, full details of Right side of column which can be found in Marlow (1984). Here a summary CS COARSE SAND of the lithostratigraphy is presented in the form of the long-profile (Fig. 1.3), from TQ895 140 to TQ903 160. Gg GRAVEL IL LAMINATIONS The depth and morphology of the underlying bedrock UNDIFFERENTIATED

.-. .- - .---m ------...---.--- ... --..--- ..------. LL I?. LL C & LL LL LL I? ..- - .-. ------..-...-.-_L ------.------L' LL. L LL LL IL L LL. LL L C LL LL L ------_..--.------__--._------..--.-.-__ ..._LCL \\\ !-- -..\\\ \\\ / / C \\\ \v\ LL ii#, -.. \,\ --- .--L L ______------iY\ ____----.---.-'l- --- &L .'L.-..------_..___------. . ---'L 1-___------+. . i-

Fig. 1.3 Pett Level long-projle 8 Martyn Waller, Paul 3. Burrin and Andrew Marlow

Brede Bridge deposits are variable, with erosional transitions strongly The sixteen boreholes (Fig. 1.4) from TQ828174 to TQ suggested by the sharp boundaries in boreholes 3,6 and 827176 at Brede Bridge reveal a polycyclic surface cut 8. The immediate post-peat deposits consist of black (7.5 into Ashdown Beds with a minimum elevation of YR N2), darkgrey (7.5 YR 3/0,4/0)and bluish grey (5B - 12.82m O.D. A thin, dissected mantle ofyellowish-red 6/1), frequently laminated clayey silts with fine sand (5 YR 518) or grey (7.5 YR N5) silty sand with gravel (between -5.42m O.D. and 1.68m O.D.). Hydrobia (usually coarse sandstone fragments) overlies part of the spp., bivalves and shell fragments are common within rockhead between - 8.16m O.D. and 1.40m O.D. This this unit. Such deposits directly overlie the blue silty clay material is buried by bluish and greenish grey (5 B 6/1,5 in boreholes 12 and 17 with the intervening peat absent. BG 5/ 1,5 G 5/2,5Y 511) clayey silts with fine sand which A thin interbedded peat with sand occurs between are generally coarser toward the valley sides and directly - 0.37m O.D. and - 0.27m O.D. in borehole 13. Above overlie bedrock in some boreholes. Such material occurs the frequently laminated deposits is a grey (5 Y 6/ l), between - 12.82m O.D. and 2.0m O.D. Over the greyish brown (10 YR 512) mottled with red (2.5 YR central part of the floodplain there follows a fining- 518) or strong brown (7.5 YR 516) silty clay with sand upward sequence, with the clayey silts being replaced by (between 0.64m O.D. and 2.60m O.D.), in which shell a blue grey (5 B 711) clay, from - 7.40m O.D. to fragments are also abundant. - 4.16m O.D. Except at the floodplain/valley-side margins inorganic sedimentation is followed by detrital Newenden peats with abundant wood remains, within which Six boreholes have been sunk across the floodplain of the impersistent lenses of greyish brown (10 YR 512) clay River Rother from TQ835267 to TQ834271 (Fig. 1.6). occur. Although organic material is found at - 7.28m Again, bedrock was only established in two boreholes (1 O.D. (borehole 6),widespread peat development occurs and 6) close to the valley-sides. In borehole 6 this surface upwards from - 5.50m O.D. The transitions from the is overlain by a light grey (5 Y 712) silty sand found underlying deposits are gradual with peaty clays and between - 7.77m O.D. and - 6.36m O.D. Elsewhere clay with Phragmites remains occurring. Organic the deepest deposits identified are bluish grey (5 B 7/1), sedimentation continues until 1.70m O.D. (borehole occasionally with black mottling, silty clays which occur 10). Beneath the contemporary channel the return to between - 14.15m O.D. and -4.23m O.D. Gradual inorganic sedimentation is marked by sharp transitions transitions predominate between these inorganic into black and dark grey (7.5 YR 210, 310, 410) sediments and the subsequent greyish brown (10 YR occasionally laminated clayey silts with sand (between 512) detrital peats with wood remains, where the -0.30m O.D. and 0.68m O.D.). The floodplain is inorganic content of the sediment matrix remains high. underlain by a stiff grey (N6, 5 Y 611) mottled with red This material extends from -5.63m O.D. to 0.62m (2.5 YR 518) and strong brown (7.5 YR 516) silty clay O.D. A dark greenish grey (5 GY 411) silty sand from 0.32m O.D. to 3.09m O.D. dominates the sequence, with the peat absent in borehole 5, occurring between - 6.30m O.D. and 0.65m Old Place O.D. In the other boreholes, peat gradually gives way to Nineteen boreholes (between TQ 880170 and TQ bluish and greenish grey (5 B 6/1,5 BG 5/1,5 G 512) and 881 180) were sunk across the floodplain of the lower dark greenish grey (5 G 411) silty clays with occasional Brede at Old Place near Icklesham (Fig. 1.5). Bedrock fine sand (between - 1.70m O.D. and 1.84m O.D.). was only proven near the valley sides with the maximum This material is followed by a grey (N6, 5 Y 6/1), depth of alluvium (12.40m O.D.) recorded in borehole mottled with red (2.5 YR 518) and strong brown (7.5 YR 13. Comparison of the north and south rockhead 5/6), clayey silt found between 0.30m O.D. and 2.78m gradients suggests that the deepest part of the bedrock O.D. surface may lie towards the north and that the section is asymmetrical. Overlying the bedrock (boreholes Small Hythe 1-4,6,18,19) is a predominantly grey (5 Y 711) or The alluvial deposits of the Rother Levels to the north of greenish grey (5 GY 61 l),mottled with red (2.5 YR 5/8), the Isle ofOxney were investigated with ten boreholes at clayey silt with fine sand (between - 5.42m O.D. and Small Hythe (Fig. 1.7),from TQ895294 to TQ893299. 1.64m O.D.). In boreholes 5, 7-9, 13, 16-1 7, the deepest Although the bedrock surface remains unproven in the sediment recorded is a blue grey (5 B 711) to greenish central part of the section, it plummets from 1.52m O.D. grey (5BG 611 ) silty clay which fines upwards into a blue at borehole 6 to greater than - 9.55m O.D. at borehole grey clay (between - 12.40m O.D. and - 3.36m O.D.). 5, over a distance of 16m. A separate shallower In borehole 16 this deposit has a high fine sand fraction (maximum depth - 3.65m O.D.) channel-like de- and between - 10.97m O.D. and - 10.79m O.D. pression in the bedrock surface occurs on the northern contains a peaty clay lens. Gradual transitions are found flank of the valley. Above this surface in borehole 2 is an between the inorganic silts and clays and the overlying olive grey (5 Y 412) silty sand (between - 6.48m O.D. detrital peat, which contains abundant wood remains and -4.89m O.D.). Beneath the central part of the and occurs between - 4.33m 0.D.and 0.61m O.D. Here floodplain the deepest deposits recorded are bluish grey inorganic material is largely confined to the transitions. (5 B 711) silty clays found between - 19.62m O.D. and Contacts from the peat to the subsequent inorganic -3.79m O.D., which after gradual transitions are Flandrian Sedimentation and Palaeoenvzronments

S RIVER BREDE 3456 11 12

m 41

Fig. 1.4 Brede Bridge

S RAILWAY RIVER BREDE N 123 45 6 7 6 9 10 11 12 13 14 iii\i

Fig. 1.5 Old Place N S RIVER ROTHER NEWENDEN

Fig. 1.6 Newenden S N SMILL HVTHEI Flandrian Sedimentation and Palaeoen~~ironment~

OXNEY

RADIOCARBON DATES {uncorrected Radiocarbon Years B.P.1 A 3560f 100 1GS/C14113 B 4845+100 IGS/C14114

Fig. 1.8 Blackwall Bridge followed by detrital peats (between -4.49m O.D. and Blackwall Bridge south of the Isle ofOxney, complement 0.92m O.D.). Inorganic inclusions are almost entirely an existing Kent County Council borehole record of absent from the peat while wood remains are abundant. 1968 (shown as borehole 5 in Fig. 1.8). The KCC In boreholes 3-5, after gradual transitions, black and borehole reached the bedrock surface at c. -28.00m dark grey (5 GY 411) clayey silts occur above the peat O.D. with the deepest deposit recorded as a greenish (found between - 1.29m O.D. and 1.66m O.D.). In grey silty sand which is replaced by bluish grey sand. boreholes I and 2 a grey (5 Y 611) and greyish-brown (l0 Similar sands were identified in borehole 4 and reach a YR 512) clay silt occurs above the bedrock and peat maximum elevation of - 4.9m O.D. These coarser respectively (between 0.95m O.D. and 2.05m O.D.). sediments are replaced by a soft bluish grey (5B 7/ 1) silty The channel-like feature in the northern part of the clay (between - 7.12m O.D. and - 3.23m O.D.). profile is filled with predominantly sandy sediments. Material similar to this overlies bedrock in boreholes 1 Between - 3.65m O.D. and 2.3m O.D., dark grey (5 GY and 7 (though found between - 1.86m O.D. and 4/ 1) and dark greenish grey (5 Y 4/11 medium sands - 1.09m O.D.). The transitions to the overlyirlg detrital occur. This material gives way to yellowish brown (10 peats are gradual; here wood remains are common and YR 5/6), mottled with yellow (l0YR 816) and very pale Phragmites is particularly abundant in borehole 3. brown (10 YR 8/4),fine to medium silty sands (between Organic deposits extend from - 3.65m O.D. to 0.39m 0.82m O.D. and 3.04m O.D.), which appear to spread O.D. Transitions to the overlying inorganic sediments laterally across the valley overlying the dark grey clayey are also generally gradual, although a particularly sharp silts in boreholes 3-5. boundary occurs in borehole 3. The post-peat sediments are variable. South of the Rother, the peat is overlain by Blackwall Bridge dark blue (5 B 4/1), black, olive grey (5Y 512) grey (5 Y Six boreholes, from TQ882257 to TQ88326 1, sunk at 611) and greyish brown silty clays which occur between 12 Martyn Waller, Paul J. Burrin and Andrew Marlow

S N THE LOCK STONE BRIDGE APPLEDORE I i I i i iiiii iii ii I

Fig. 1.9 Royal Military Canal

- 1.07m O.D. and 1.10m O.D. and contain Hydrobia B 611) to grey (5 Y 511) silty clay overlies the peat from spp. and shell fragments. To the north such material - 3.34m O.D. to 1.24m O.D.; a similar deposit is found only occurs as a thin band above the peat, with light grey above the lower blue silty sand in borehole 14. South of brown (10 YR 612) and light olive brown (2.5 Y 516) the Isle of Oxney above the peat a very dark grey (2.5 Y silty sands occurring between - 0.90m O.D. and 0.61m N3/) to dark grey ((N4/) and black, usually laminated O.D. A similar yellowish brown silty sand occurs just silty sand occasionally with clay is found from - 7.49m beneath the floodplain soil (0.62m O.D. to 0.32m O.D.) O.D. to 2.50m O.D. Similar deposits north of the Isle of in borehole 2. Oxney overlie the upper blue grey silty clays (except in borehole 10) and directly overlie the peat in boreholes 16 The Royal Military Canal and 18. An additional thin (34cm) peat lens occurs Eighteen boreholes have been sunk along the edge of the above O.D. in boreholes 3, 14 and 16. In boreholes 5-9 Royal Military Canal (Fig. 1.9), from the old cliff-line and 17 a dark grey (5 Y 411) and dark greenish grey (5 near The Lock (TQ 934243) to Appledore (TQ GY 411) medium sand with silt dominates the sequence 953287). Bedrock was reached at the ends of the section occurring from - 7.18m O.D. and 1.06m O.D. A grey (5 and in the vicinity of the Isle of Oxney at Stone Bridge Y 4/1), strong brown (7.5 YR 516) and yellowish brown (borehole 11). Two boreholes quoted in Shephard- (l0 YR 5/6) silty sand and silty clay occurs as the upper Thorn et al. ( 1966) from near The Lock (TQ936245) unit (between 0.25m O.D. and 3.70m O.D.) across the both reached bedrock at c. 13m below ground level. In section. the boreholes described here, a greenish grey (5 G 511) silty clay overlies the bedrock in borehole 18 (between Stone Bridge to Snargate - 2.55m O.D. and - 1.87m O.D.). In boreholes 24 Thirteen boreholes (Fig. 1.10) reveal the nature of the and 14-16 the deepest deposits consist ofdense blue grey alluvial stratigraphy between Stone Bridge (TQ (5 B 611) to dark grey (N4/) silty sands and sands, which 946265) east of the Isle of Oxney and the Rhee Wall at are found between - 6.02m O.D. and - 3.03m O.D., Snargate (TQ989290). Bedrock was only recorded in and appear to coarsen with depth (which prevented borehole 1 near the Isle of Oxney. Elsewhere along the deeper penetration). Such deposits are usually overlain line of this section penetration below - 5.37m O.D. was by a blue grey (5 B 611) silty clay (from - 6.00m O.D. to prevented by the presence of dense bluish grey (5 B 71 1) - 2.16m O.D.); the boundary between these sediments silty sands and dark bluish grey (5 B 411) sands which is almost imperceptible suggesting a fining upward occur to a maximum elevation of - 1.90m O.D. These sequence. There is a variable transition from the blue sands are usually superseded, after gradual transitions, clay into a detrital peat where wood remains are by bluish grey (5 B 711) silty clays (between -4.58m common and inorganic inclusions rare. Organic O.D. and - 1.17m 0.D.).The transitions to peat which material occurs between - 3.42m O.D. and -0.27m follow are variable, with some sharp contacts occurring, 0.11. The upper contact of the peat is also variable notably where the blue sand and peat are adjacent though sharp boundaries predominate. To the north of (borehole 10). The peat, largely detrital with wood the Isle of Oxney (boreholes 10-1 3 and 15) a blue grey (5 remains, occurs between - 3.63m O.D. and 0.02m O.D. Flandrian Sedimentation and Palaeoenvironments

SW

ISLE OF STONE BRIDGE BECKET'S BRIDGE RHEE WALL OXNEY AT SNARGATE 4 1234 5 8 9 10 11 m*.. . . m

Fig. 1.10 Stone Bridge to Snargate

In three boreholes (4,5,7) the upper part of the peat is of a grey (5 Y 6/1), greyish brown (10 YR 512) and highly humified. The upper contacts of the peat are strong brown (7.5 YR 516) sandy and clayey silt generally gradual, although sharp transitions are (between -0.58m O.D. to 3.01m O.D.). The upper evident in boreholes 6 and 7. Black, dark bluish grey (5B sediments which occur north-east of the Rhee Wall are 4-11) and dark grey (7.5 YR N4/,N3/) occasionally described in the following section. laminated, interbedded sands, silts and clays overlie the peat, occurring from - 3.87m O.D. to 1.84m O.D. The Rhee Wall at Snargate These deposits appear to become finer and thinner in a Six boreholes were sunk adjacent to and across the Rhee north-easterly direction (boreholes 8-12), and have not Wall (Fig. 1.1 1) in the vicinity of Snargate (from TQ been recognised north-east of the Rhee Wall. In 986287 to TQ 989290). Here, firm sands prevented borehole 9 a thin peat lens occurs above O.D. In penetration below a depth of - 4.60m O.D. The deepest borehole 2 the sedimentary sequence is dominated by a deposits consist of a bluish grey (5 B 711) silty sand and dark grey (5Y 411) sand from the base at - 3.69m O.D. dark bluish grey (5 B 411) sand (borehole 2) which have to 2.06m O.D. This material is overlain by a yellowish a maximum elevation of - 1.70m O.D. A fining brown silty sand. Similar material also occurs in upwards sequence into a bluish grey (5 B 711) silty clay borehole 1. More usually, the uppermost deposits consist (from - 2.55m O.D. to - 1.83m O.D.) then occurs,

ROAD SEWER 2 3 I :I 5

-61 Fig. 1.11 The Rhee Wall at Snargate 14 Martyn Waller, Paul 3.Burrin and Andrew Marlow though the variation between the individual boreholes is predominantly grey (5 Y 6/1), light grey (5 Y 611) and marked. After gradual transitions, where the remains of greyish brown (10 YR 512) mottled, sometimes Phragmites are abundant, a predominantly detrital peat laminated, clayey silts with sand found between with wood is found (between - 1.97m O.D. and 0.10m - 0.06m O.D. and 2.75m O.D. No distinctive sediments O.D.). The upper contact of the peat is variable. To the peculiar to the Rhee Wall were distinguished. north-east of the Rhee Wall the peat is overlain by light yellowish brown (2.5 Y 614) and yellowish brown (10 YR 516) medium sands, which occur between - 0.13m Alluvial lithostratigraphy O.D. and 1.60m O.D. On the Rhee Wall and to the From the descriptions of these sections it has been south-west the post-peat deposits are varied, with dark possible to identify and attempt to correlate a series of bluish grey (7.5 YR N4/,N3) clayey silts (boreholes 1 lithostratigraphic units which appear to comprise the and 3) and sands (borehole 2) and a dark grey to black alluvial stratigraphy of this area. These are outlined in silty clay with abundant shell fragments (borehole 4) Table 1.1 and form the basis from which the schematic occurring above the peat (-0.68m O.D. to 0.75m sections presented in Figs. 1.12-1.16 have been O.D.). These deposits are in turn overlain by constructed.

Table 1.1 Generalised lithostratigraphy of the deposits. Fig. 1.12a Key to Schematic Sections, Figs. 1.12-1.16, Unit Describtion

12 Soil and disturbed ground. 12 SOIL AND DISTURBED GROUND 11 Undifferentiated sands. 10 Undifferentiated silts and clays. Littoral sands and gravels; found only in contemporary U UNDIFFERENTIATED SANDS near-shore environments, such as the lower Brede (Fig. 13).

Grey and brown, mottled with strong brown and red, UNDIFFERENTIATED SILTS AND CLAYS sands, silts and clays. These frequently form the uppermost unit and usually extend the full width of the section. Medium grey sands; which are usually dense, structureless LITTORAL SANDS AND GRAVELS and well sorted. Black and grey (frequently laminated) sands, silts and clays. GREY AND BROWN, MOTTLED WITH STRONG This is a variable deposit which is characterised by its BROWN AND RED, SANDS, SILTS AND CLAYS colouration, sedimentary structure and stratigraphic position. While the laminations are an inconsistent feature, MEDIUM GREY SANDS both in occurrence and appearance, they usually consist of fine sand lamina of < 1 mm, separated by interstitial clays and silts of variable width. Similar structures composed of BLACK AND GREY (FREQUENTLY LAMINATED) laminated peat were also observed. SANDS, SILTS AND CLAYS Peat; which usually consists of coarse fragments of plant material (detrital sensu Troels-Smith 1955) with wood and PEAT Phragmites remains. Intercalated inorganic layers also occur. BLUISH-GREY CLAY Bluish grey clay; found underlying the peat. B Bluish grey sand; which ranges in texture from silty sand to coarse sand and is generally dense. It forms the deepest BLUISH-GREY SAND deposit recognised on the marshland. Basal sands and gravels; which usually consist of weakly cemented fine angular sandstone grits and gravels in a BASAL SANDS AND GRAVELS matrix of sands and silts. Bedrock; clays, silts and sandstones ofthe Lower Cretaceous Hastings Beds Group. It should be emphasised that the chrono-stratigraphic relationships between these units have not been fully defined. This topic is considered later in some detail. Flandrian Sedimentation and Palaeoenuironments

Fig. 1.12 Pett Level long-projle

m SEOLESCOMBE CAMBER 8 CASTLE

4 1

0.0. -0.0.

-4

-8

-12

RAOIOCARBON DATES (uncorrected Radlocarbon Years B P) A 3690f 70 SRR 2645 B 5970 *l50 SRR 2646 C 1830f 80 SRR 2893

Fig. 1.13 Lower Brede Valley long-projle

S N BREDE BRIDGE ? 3456 7. 8 . ? 10. 11.. 12 13 l$ 1:!6 RIVER BREDE m I

-O.D.

-8

RADIOCARBON DATES Fig. 1.14 Lower Brede Valley sections -12 (uncorrected Radlocarbon Years B.P.) A 3690' 70 SRR 2645 B 59702150 SRR2646

S N OLD PLACE l? 1.6 l 1.8 1.9 !?3?56 ? 51 ? 'p 1 l? 1.3 l? RAILWAY RIVER m

0.0.

------...... - 8 .------.------.------.------12 ---- -.- 0 loom Martyn Waller, Paul J. Burrin and Andrew Marlow

S NEWENDEN

1 2 4 RIVER ROTHER 5 ! NEWENDEN

S SMALL HYTHE

10 ISLE 1 ? 5:: B ? READING SMALL OF SEWER HYTHE OXNEY i i 1 - O.D.

...... ------8 .------. ------p------.------. -. I ------.------. - -12 ------.------. - .------.------16 ------. -----

S BLACKWALL BRIDGE. WITTERSHAM ? ? ? ! ? OTTER RIVER ISLE OF CHANNEL ROTHER OXNEY

Fig. 1.15 Lower Rother Valley sections Flandrian Sedimentation and Palaeoenuironrnents 17

S N ROYAL MILITARY CANAL l? 1.3 14 12 lfj 1.7 18 ? 8 APPLEDORE 1

O.D.

......

......

SW RHEE WALL AT SNARGATE

SW NE STONE BRIDGE TO SNARGATE 13 ISLE OF l?? ? 5 6 ? 8 ? l? l? OXNEY m ST~NEBRIDGE BECKE?'S BRIDGE rHEE ,WALiAT SNARGATE I O.D. - 0.D

-4 ......

Fig. 1.16 Western Marshland sections

Sedimentology At the outset of this investigation little was known Unit 4: bluish-grey clay (Snargate, borehole 5, -4.50m regarding the more detailed sedimentological character- to - 4.00m O.D.; Small Hythe, borehole 3, - 6.00m istics of the deposits of the marshlands and the adjacent O.D. to - 5.50m O.D.); valleys. Consequently, a selection of samples was chosen Unit 6: black and grey laminated sands, silts and clays in order to investigate the grain size distributions ofsome (Royal Military Canal, borehole 1, - 6.90m O.D. to of the units found comprising the lithostratigraphy. This - 5.90m 0.D; Rhee Wall, borehole 3, - 0.25m O.D. to forms but a start to resolving the complex problems 0.25m O.D.); concerning the possible sources of the sediments, their spatial variation and likely depositional environments. Unit 7: grey sand (Royal Military Canal, horehole 5, Five of the main inorganic units identified in the - 1.95m O.D. to O.D.; borehole 9, - 3.0m O.D. to lithostratigraphy (Table 1.1) were chosen for investig- - 2.10m O.D.); ation. These included samples of: Unit 8: grey and brown mottled sands, silts and clays Unit 3: bluish-grey sand (Rhee Wall, borehole 1, (Royal Military Canal, borehole 1, 0.91m O.D. to -4.00m O.D. to - 3.50m O.D.; Royal Military Canal, 1.31m O.D.; borehole 6, 2.16m O.D. to 2.66m O.D.; borehole 2, - 5.50m O.D. to - 4.50m O.D.) Snargate, borehole 3, 1.43m O.D. to 1.83m O.D.). 18 Martyn Waller, Paul 3. Burrin and Andrew Marlow

Blue Sand Blue Clay Black Laminated Sands and Silts % %

Grey Sand Grey Mottled Silty Sands an

Fig. 1.l7 Grain-size distributions

Table 1.2 Moments of the grain size distributions for the deposits.

SAMPLE LOCATION M 1 M2 M3 M4 mean sorting skewness kurtosis

Blue Sand Rhee Wall 3.994.06 0.54-0.59 0.13-0.22 1.28-1.39 MS PSk L KEY Royal Military 4.10-4.18 0.74- 0.77 0.19-0.20 0.83-0.87 M2 (sorting) Canal MS PSk P MS = moderately PS = poorly Blue Clay Small Hythe 4.234.85 1.20-3.22 -.04 to .04 1.50-3.94 VPS = very poorly PS-VPS NSym L-VL WS = well Snargate 5.48-5.79 1.64-1.80 0.21-0.40 0.85-0.99 VWS = very well PS-VPS P-VPSK P-M

Black & Grey Royal Military 3.84-3.88 0.28-0.37 -.51 to -.69 1.28- 1.38 M3 (skewness) Canal WS-VWS VNSk L PSk = positively Sands & Silts Rhee Wall 4.06 0.95 0.09 1.07 VPSk = very positively MS NSym M NSym = nearly symmetrical VNSk = very negatively Grey Sand Royal Military 3.264.28 0.494.89 0.08-0.31 0.85- 1.06 Canal MS NSym-VPSk P-M M4 (kurtosis)

L= leptokurtic Grey Mottled Sands Small Hythe 5.97 2.53 0.59 0.88 VL = very leptokurtic VPS VPSk P M = rnesokurtic Silts & Clays RoyalMilitary 4.63-5.59 1.29-1.69 0.44-0.68 0.70-1.59 P= platykurtic Canal PS VPSk P-VL Snargate 4.86 1.36 0.48 1.05 PS VPSk M Flandrian Sedimentation and Palaeoenzlironments 19

The samples were all subjected to standard pretreat- mean grain size range of 3.26 to 4.28 +) and is dominated ments and dispersion prior to analysis by the hydrometer by very fine sand (c. 48% at 63p) and coarse silt method (British Standards Institute, No 1377). The (43-497; at 54p). It is moderately sorted (Table 1.2), grain size distributions and their moments were then ranges from being nearly symmetrical to very positively calculated using a micro-computer employing the skewed and has a platykurtic to mesokurtic distribution. equations of Folk and Ward (1957). The results are There are insufficient differences to allow this unit to be presented as cumulative grain size distributions (Fig. separated sedimentologically from the laminated 1.17), with the corresponding moments in Table 1.2. deposits using these analytical methods. Interpretation of these results has to take into account a number of factors. First, the bedrock sources of sediment are significant in that these determine the initial grain size distributions and moments of the materials available Pollen and Plant Macrofossil Investigations for transportation and subsequent reworking by a range Pollen and plant macrofossil investigations have been of geomorphic processes. Second, reworking can undertaken as part of a study into the Flandrian significantly alter or modify the characteristics of the vegetational history of the Brede and Pannel valleys. source materials so that it is possible to suggest the The organic deposits ofsix sites, one at Brede Bridge (TQ environment of deposition. Finally, reworking of 829174), four from Old Place (boreholes 2 and 5, TQ previously deposited sediments can further modify their 880 17 1; borehole 7 TQ 880 172; and borehole 13 TQ characteristics. Hence, the sedimentology of a lithostrat- 881 176) and one from Pannel Bridge (TQ882152) have igraphic unit needs to be considered and interpreted been intensively studied. Details of the techniques alongside other lines of evidence and enquiry in order to employed and a full discussion of the vegetational maximise its potential value for palaeoenvironmental history will be published elsewhere. This section will reconstruction. focus on aspects of this work which are relevant to an The blue sand has a mean particle size range of3.99 to understanding of the sedimentary development of these 4.18 C$ (fine sand/coarse silt), is moderately sorted, valleys. positively skewed and is platykurtic to leptokurtic. The One of the major problems in reconstructing past samples are dominated by very fine sand (c. 45% 63p), vegetation from peats in the coastal zone using pollen the remainder of the distribution consisting ofsil ts with a assemblages arises from the difficulty of distinguishing high coarse silt component (c. 45%). provenance for many of the pollen types. In this study The blue clay samples were found to be comprised plant macrofossils have been used to complement pollen largely of silt (the samples analysed here consisted of analysis, allowing the past vegetation of the sites studied only 48% clay [< 2p]), with a variable very fine sand to be determined and so facilitating the separation of the content of up to c. 15%. The 'clay' has a mean grain size valley side and local pollen components. The conditions range from 4.23 to 5.79 +, is poorly to very poorly sorted, which seem to have prevailed on the Brede floodplain has a symmetrical to very positively skewed distribution during the major phase of peat accumulation (c. 6000 and a variable kurtosis, ranging from platykurtic to B.P. to c. 3700 B.P.) can therefore be outlined. extremely leptokurtic. Interestingly, the grey mottled At four sites (Brede Bridge, and Old Place boreholes 5, with strong brown sands, silts and clays appear to exhibit 7 and 13) the transition from inorganic to organic similar characteristics to that displayed by the blue clay sedimentation is marked by a change from salt-marsh to (Fig. 1.17), having a similar mean grain size range (4.63 freshwater communities. High frequencies of Cheno- to 5.97 +), being poorly or very poorly sorted, very podiaceae pollen occur prior to peat formation and positively skewed and ranging in kurtosis from 0.70 to Plantago maritima and Armeria grains are also present. The 1.59 (platykurtic to very leptokurtic). It is also seeds of Suaeda maritima were found at Brede Bridge. The noteworthy that some of the samples have a primary onset of peat accumulation is accompanied by a rapid peak in the coarse silt (54p) fraction. This is a persistent rise in Alnus pollen. The remains ofAlnusglutinosa (pollen and significant characteristic found in the inland and macrofossils) then dominate throughout most of the floodplain and valley fill alluvium (see Burrin 1988) and period of peat formation. Several fen associated shrubs suggests that at least part of these units have been occur in both the pollen and macrofossil assemblages, derived from or supplied by fluvial activity. including Rhamnus catharticus, Frangula alnus, and The grey and black laminated sands, silts and clays Viburnum opulus. The macrofossil record also contains have a mean grain size range of 3.84 to 4.06 4, are many fen associated herbaceous types. of which moderately to very well sorted, very negatively skewed Filipendula ulmaria, Lycopus europaeus, Rubus sp., Rumex sp., or nearly symmetrical and mesokurtic to leptokurtic in Oenanthe sp., Chenopodiaceae, Ranunculus sp., and Carex their distribution. These findings are of limited sp. are prominent. Other herbs, unambiguously relevance as bulk samples were analysed thereby mixing associated with fen conditions, which are well sand and silt laminae which may have very different represented in the pollen record during organic distributions if considered separately. Nevertheless, this accumulation include Lythrum, Lysirnachia vulgaris, unit contained high total sand contents of40-50%, with Galium type, Valeriana, Chrysosplenium and Solanum up to l l at 125p and c. 3540% at 63p, the remainder dulcamara. Several aquatic pollen types are common, of the distribution consisting of silts. The grey sand has a particularly Alisma and Typha angustifolia type. The Martyn Waller, Paul 3.Burrin and Andrew Marlow

Table 1.3 Radiocarbon dates from the Romney Marsh area

Wheelsgate, Old Romney Shells from creek filling at c. + 3m TR 024237 1550f 120 B.P. Callow et al. 1964 O.D. Old Place, Icklesham Transition from peat to upper estuarine deposit at -1.16m O.D. Scotney Court Farm, Lydd From 2" thick peat layer overlying TR 023202 2050 f 90 B.P. Callow et al. 1966 clay with roots Pannel Bridge, Pett Peat at + 1.36m O.D. TQ882152 2670f 80 B.P. Waller 1987 Scotney Court Farm, Lydd Roots in clay c. + 3.0m O.D. TR 023202 2740f 400 B.P. Callow et al. 1966 Pannel Bridge, Pett Peat at + 0.38111 O.D. TQ882152 2980 f 80 B.P. Waller 1987 Higham Farm, Kenardington Wood in peat at c. + 3m O.D. TQ977308 3020f 94 B.P. Callow et al. 1964 Court Lodge, Old Romney Wood in peat at c. + 3m O.D. TR 032243 3340 f 92 B.P. Callow et al. 1964 Blackwall Bridge, Peat at c. 1.5m O.D. TQ885258 3560 f 100 B.P. Weliri et al. 1971 Wittersham Brede Bridge, Brede Peat (Tilia decline) at +0.4m. O.D. TQ829174 3690 f 70 B.P. Waller 1987 Pannel Bridge, Pett Peat ( Tilia decline) at -0.76m 0.1). TQ882152 3700f 90 B.P. Waller 1987 Roman fort, Lympne Wood in colluvium at 6.3m O.D. TR 116342 4400f 50 B.P. Hutchinson et al. 1985 Blackwall Bridge, Peat at c. -2.8m O.D. TQ885258 4845 f 100 B.P. Welin et al. 1971 Wittersham Pannel Bridge, Pett Peat (Ulmus decline) at 3.42111 O.D. TQ882152 5040f 80 B.P. Pett Level, Pett Wood from submerged forest at TQ889140 5205f 105 B.P. Welin et al. 1972 approx. O.D. IGS/C14/56 Pett Le.del, Pett Peat from submerged forest at approx. TQ889140 5300f 100 B.P. Welir~et al. 1972 O.D.

SRR.2889 Pannel Bridge, Pett Peat at - 4.22m O.D. TQ882152 5540f 80 B.P. Waller 1987 SRR.2646 Brede Bridge, Brede Transition from hyposaline clay to TQ829174 5970f 150 B.P. Waller 1987 peat at -5.35m O.D. SRR.2890 Pannel Bridge, Pett Peat at - 6.14m O.D. TQ882152 7000f 90 B.P. Waller 1987 SRR.2891 Pannel Bridge, Pett Peat at - 7.61m O.D. TQ882152 9380f 100 B.P. Waller 1987

IGS/C14/116 Tilling Green, Rye Peat at - 22.5m O.D. TQ915206 9565 f 120 B.P. Welin et al. 1974 SRR.2892 Pannel Bridge, Pett Peat at - 8.42m O.D. TQ882152 9960f 110 B.P. Waller 1987

spores of Osmunda and Polypodium are also abundant in all occurs in many Flandrian pollen diagrams has long been the Brede valley diagrams. recognised to be diachronous (Turner 1962). Despite The pollen and plant macrofossil assemblages suggest this, the decline in lime frequencies over such a small the floodplain environment resembled modern alder area may prove useful as a chronostratigraphic marker. carr (the Osmundo-Alnetum communities of Wheeler The two dates available for this event, from Brede Bridge 1980) during most of the period of peat accumulation. (3690f 70 B.P. SRR. 2645) and Pannel Bridge The peat deposits of the Brede valley are therefore (3700f 90 B.P. SRR. 2887), are in close agreement, clearly autochthonous, although they have been largely with a rapid and permanent decline in Tilia values defined as detrital (sensu Troels-Smith 1955). occurring. Three of the diagrams from Old Place Despite the problems of using pollen zones to provide (boreholes 2, 5 and 13) show a distinct fall in Tilia a relative chronology in the Flandrian, two changes in percentages prior to the deposition of the upper biostratigraphy, the Ulmus (elm) and Tilia (lime) inorganic sediments. However, in borehole 7 the high declines, may be useful as chronostratigraphic markers Tilia frequencies persist until this contact. This provides with which to compare sequences from the different sites further evidence for erosion of the upper surface of the examined. The decline in Ulmus over north-west Europe peat (see also Fig. 1.5) and illustrates the need for the appears to be synchronous at about 5000 B.P. (Smith careful assessment of such transitions if they are to be and Pilcher 1973; Huntley and Birks 1983). At Pannel subject to radiocarbon assay. It is also possible to infer Bridge this event has been dated to 5040 f 80 B.P. (SRR. that a thin peat, laminated with inorganic material, 2888) (Table 1.3). Such a decline in Ulmus frequencies which occurs between - 0.27m O.D. and - 0.37m O.D. occurs at four further sites from this area: at Brede Bridge in borehole 13 on the Old Place section, was derived ( at - 3.29m O.D.) and Old Place boreholes 5 ( - 2.34m from the erosion of material deposited during the main O.D.),7 (-2.71m0.D.) and 13 (-3.53mO.D.).Inthe phase of peat accumulation, as high Tilia values were absence of radiocarbon evidence the initiation of peat recorded. growth in the lower Brede valley at Old Place prior to Although they show the transition from salt-marsh to 5000 B.P. can therefore be inferred. In contrast to the alder-carr, the heights of the lower contact of the peat at Ulmus decline, the fall in Tilia pollen frequencies which Old Place in boreholes 5 (- 3.45m O.D.) and 7 Flandrian Sedimentation and Palaeoenuironrnents 2 1

(- 3.36m O.D.) are markedly different from borehole However, the dramatic changes in pollen assemblages 13 (at -4.17m O.D.), matching the variations in which occur with the Tilia decline suggest widespread elevation at which the LJlmus decline was recorded. This forest clearance. Both at Brede Bridge and Pannel Bridge can be used to suggest that these differences are the result organic accumulation continues beyond these changes, of post-depositional changes in altitude (rather than, for though wetter conditions seem to have prevailed in the example, representing diachronous growth over an local environment. This is consistent with an increase in uneven pre-peat surface), possibly reflecting the surface run-off which might be expected after the quantity of compressible material above the pre- removal of forest cover (Limbrey 1978, 1983). That Flandrian surface. The differences in relative elevation widespread forest clearance cannot be shown to have between the Tilia decline at Brede Bridge (0.40m O.D.) resulted immediately in a direct change in sediment- compared with Old Place, near the valley side (0.04m ation may, in addition to lag prior to the onset of any soil O.D. in borehole 2) and the centre of the valley erosion, be due to the presence ofsediment stores within (- 1.67m O.D. in borehole 13),shows the degree ofpost- the fluvial system (Brown and Barber 1985), or reflect depositional change in altitude which can occur below complex response mechanisms (Burrin and Scaife 1984, thick post-peat deposits. Comparison of the quantity of 1986). The sedimentary consequences of such events sediment found between the chronostratigraphic appear particularly difficult to detect in perimarine and markers, the elm and lime declines, at Old Place coastal environments, where they may influence, and be borehole 5 (0.88m) and borehole 13 ( 1.90m), and Brede masked by, changes in other external environmental Bridge (3.69m), suggests post-depositional compaction factors. relative to Brede Bridge of c. 76% has occurred in borehole 5 and c. 49% in borehole 13. These may be considered as minimum estimates as some autocompac- tion could have occurred at Brede Bridge. A comparable Foraminiferal Investigations correction (5094) to allow for the compaction and The inorganic sediments of Pett Level and the Brede consolidatio~iof peat was suggested by Devoy (1982) valley at Old Place and Brede Bridge have been subject from a review of the literature, while Smith (1985) to detailed foraminiferal investigations. Subsidiary applied corrections of 40-50% to the Flandrian samples were also taken from the upper Brede valley and sediments of the Nar valley (Norfolk) from the from near Stone Bridge. Material was collected using a oedometer test. lOcm diameter gouge auger and sub-samples of The radiocarbon dating of the upper contact of the approximately 250 grams (dry weight) were taken for peat at Old Place in borehole 5 ( - l.l6n1 O.D.) to analysis. Full details of the techniques employed can be 1830d~80 B.P. (SRR. 2893) is surprising in that the Tilia found in Marlow (1984).Each sample was analysed and decline (c. 3700 B.P.) was found at - 1.46m O.D. If the the taxonomic composition determined. Foraminiferal lime decline can be used as a reliable chronostrati- assemblages were then compared to those recorded from graphic marker in this area, then a considerable hiatus contemporary North West European environments (though possibly exaggerated by compaction) may have (Feyling-Hanssen et al. 197 1, Murray 1973, Hayries occurred towards the end of the organic accumulation. 1973). Five principal palaeoenvironments were re- This is supported by the relative lack of post-Tilia cognised, characterised by foraminiferal assemblages decline sediments at Brede Bridge (only a further metre and associated lithological characteristics (Table 1.4). was recorded), where the upper inorganic sedirnents are These assemblages have component similarities to those largely absent. Although the radiocarbon date may be in recorded by Haynes and Dobson (1969), Murray and error, the depth of the sample (3.66m below ground Hawkins (1976), and Culver and Banner (1978). level) suggests contamination from recent material is unlikely. One radiocarbon assessment is clearly an Pett Leuel inadequate basis for determining the date of this contact. Four sites have been investigated at Pett Level. Here the A third area where pollen analysis may elucidate the results from one borehole (TQ901152) have been taken sedimentary development of this area concerns the as an example of the type of foraminiferal assemblages impact of man's activities on the environment. Both the found. Details of differences within the assemblages Ulmur and Tilia declines have been ascribed to the recorded from Prtt Level and interpretation of such activities of man. In this area widespread clearance spatial variations can be found in Marlow (1984). during the elm decline is not apparent from the pollen Two samples (- 4.40m O.D. and - 4.10m O.D.), assemblages, though at both Brede Bridge and Pannel were taken from the blue sand (unit 3). The Bridge inorganic lenses in the li thostratigraph y are foraminiferal assemblage is co-dominated by the coincident with this event. Such layers, however, are not euryhaline species Protelphidium germanicum (58% and confined to this period and tend to be laterally 60%) Elphidium zvilliamsoni (74, and 10%). The residue impersistent (see Fig. 1.4).It is not possible, therefore, on of taxa represent a mixed death assemblage with a small the basis of their presence to infer an increase in sediment number of stenohaline (open marine) species (Ammonia supply as a result of anthropogenic activity in the area. batavus, Miliolinella subrotunda and Boliuina pseudoplicata) They may simply be a product of channel migration or and hyposaline species ( Trochamrnina infata and avulsion. Jadammina macrescens) present. These species exhibit 22 Martyn Waller, Paul 3. Burrin and Andrew Marlow

Table 1.4 Principal environments as indicated by in situ of P. germanicum remains significant within all foraminiferids assemblages but gradually declines up-core; from 60% at the blue sandlblue clay contact to 4O0lOat the blue A. Supralittoral (supratidal) No marine foraminifera claylpeat interface. The dominance of P. germanicum and B. Littoral (intertidal) the presence of Ammonia tepida, and Elphidium williamsoni, Marsh Trochammina inflata (Montagu) together with several stenohaline species at the base of Jadammina macrescens (Brady) the blue clay (- 3.60m O.D.) suggest deposition within High mud flats Ammonia tepida Cushman a high mud flat environment open to marine influence. Elphidium williamsoni Haynes The up-core increase in the dominance of the three main Protelphidium germanicum (Ehrenberg) hyposaline species, with a concomitant reduction in Low mud flats Elphidium williamsoni Haynes marine elements, indicates a gradual transition from a Protelphidium germanicum (Ehrenberg) high mud flat to a low energy intertidal marsh C. Littora1,'sublittoral environment prior to peat formation. Intertidal sandflats Ammonia batavu Hofker Nine samples (-0.90m O.D., -0.55m O.D., Cibicides lobatulus (Walker and -0.30m O.D., -0.10m O.D., 0.30m O.D., 0.60m Jacob) Elphidium selseyense (Heron-Allen and O.D., 1.00m O.D., 1.50m O.D. and 2.30m O.D.) have Earland) been examined from the post-peat sediments (units 6 Elphidium williamsoni Haynes and 8). These assemblages are dominated by the Protelphidium germanicum (Ehrenberg) euryhaline species P. germanicum (40% to 70%). The (Luinqueloculina seminulum (Linne) hyposaline species T. injata (20% to 25%) and 3. D. Sublittoral (marine) macrescens (2 1 to 24%) are well represented close to the Ammonia batavus Hofker upper contact of the peat, but are then replaced by a Bolivina pseudoplicata Heron-Allen slight rise in the brackish water species E. williamsoni, E. and Earland Brizalina variabilis (Williamson) articulatum and A. tepida and some stenohaline species Brizalina pseudopunctata (Hoglund) (Brizalina variabilis, Miliolinella subrotunda and Cyclogyra Elphidium clavatum (Cushman) involvens). Hyposaline species continue to be present in Elphidium selseyense (Heron-Allen and small quantities up to 1.00m O.D. Both stenohaline and Earland) hyposaline elements exhibit etched and size sorted tests Miliolinella subrotunda (Montagu) Cibicides lobatulus (Walker and suggesting some local intra-environmental transport- Jacob) ation. These assemblages suggest an environmental Spirillina viuipara Ehrenberg transition from intertidal marsh (at the peat contact) to deposition within a low energy sand flatlmud flat aberrant size distributions and surface etching of tests environment. The low species diversity and specimen which suggests some intra-environmental transport- density recorded from the post-peat deposits indicates ation and local reworking of both littoral and sub- some ecological stress which may be explained by high littoral sediments. Many of the stenohaline species and variable sedimentation rates and some fluctuation appear to correspond to the dominant grain-size in salinity levels. Such unstable conditions can also be suggesting selective marine transportation. A slight inferred from the presence of laminations, which usually reduction in the number of stenohaline specimens at consist of fine sands interbedded with silts and clays. -4.10m O.D. was observed. The foraminiferal and These are indicative of variable flow velocities and their lithological evidence, therefore, suggests that deposition preservation suggests a degree of environmental probably took place in a transitional area between the protection and the suppression of benthic fauna by rapid low mud flat and sand flat environments. The up-core deposition and/or toxic bottom conditions. fining of the sediments and the reduction in stenohaline specimens indicate a decrease in environmental energy Old Place and a reduction in access to open marine conditions in The foraminiferal content of two cores (borehole 3 TQ the proximity of the blue sandlblue clay contact. 8801 71 and borehole 13 TQ 881 176) have been Samples at - 3.60m O.D., - 3.15m O.D. and - 2.5m examined from the Old Place section in the Brede valley. O.D., from the blue clay (unit 4), are dominated by Foraminifera were absent from the sub-samples taken three main species; the euryhaline P. germanicum (40% to between - 3.25m O.D. and - 1.32m O.D., a grey silty 60%) and the hyposaline Trochammina injata (10 to sand (unit 10) above bedrock in borehole 3, suggesting 20%) and Jadarnrnina macrescens (10 to 20q',). Stenoh- that deposition probably did not occur under the aline species occur at levels of less than 5% (e.g. Spirillina influence of marine conditions. vivipara, Brizalina variabilis, Cyclogyra involvens and Bolivina More extensive investigations were carried out in the pseudoplicata) adjacent to the blue sand and blue clay inorganic deposits of borehole 13. Four samples interface (- 3.60m O.D.). This stenohaline component (-5.57m O.D., -5.27m O.D., -4.87m O.D. and within the recorded assemblages gradually declines and - 4.37m O.D.) were taken from the pre-peat deposits, is vertically replaced by the increasing dominance of the the blue clay (unit 4). The deepest sample (- 5.57m hyposaline species T. injata and 3. macrescens in the O.D.) revealed a superabundance of P. germanicum proximity of the blue claylpeat interface. The presence (80%) and a small number of mixed stenohaline (i.e. Flandrian Sedimentation and Palaeoenvironments 23

Brizalina pseudopunctata, Gavelinopsis praegeri and I.agena Walland Marsh clavata) and hyposaline species (T. injata and 3. A sample from the Stone Bridge to Snargate section macrescens). A significant up-core reduction in the (borehole 2, TQ949264) was taken from the medium presence of P. germanicum (falling from 80% to 5%) and grey sands (unit 7) at 0.81m O.D. The mixed death an increase in the dominance of the hyposaline species in assemblage recorded contains twenty-one different the proximity of the blue clay/peat interface was noted. brackish water or stenohaline species including P. This evidence suggests an up-core transition from a mud gerrnanicurn (230/,), Ammonia batavus (16%), Quin- flat environment (at - 5.57m O.D.) to an intertidal queloculina seminulum (6%), Miliolinella subrotunda (5%), marsh adjacent to the lower contact of the peat. Elphidium cuvillieri (6%), Massilina secans (5%) and Six samples ( - 1.25m O.D., - 1.15m O.D., - 0.35m Elphidium selstyense (6%). This suggests that deposition O.D., 0.25m O.D., 1.05m O.D., and 1.85m O.D.) were probably took place within a littoral or sub-littoral sand analysed from the post-peat deposits (units 6 and 8). flat environment, with a higher environmental energy These assemblages are again dominated by P. germanicum than those associated with the other inorganic sediments (32% to 73y0) associated with a small number of investigated as part of this study. It is believed that the brackish water and stenohaline species. The hyposaline mobility of sand within this environment may have species 7. inzata (29%), 3. macrescens (16%) and the precluded indigenous habitation; hence, there is no euryhaline P. germanicum (42%) are dominant close to opportunity for fauna1 domination by species as found in the the upper peat contact. The hyposaline species are lower energy environments. replaced up-core by brackish water and stenohaline species and by the increasing dominance of P. germanicutn. At 0.25m O.D. there is a slight reduction in P. germanicum associated with a rise in the stenohaline Discussion marine inner shelf species Quinqueloculina serninulum (570), Massilina secans (14%), B. variabilis (jc;<),The Flandrian Deposits Gavelinopsis praegeri (5':b), Spirillina vivipara (5%), Amongst the deepest deposits recognised within the EQhidiurn crispum (676) and Ammonia balaous (8%), lower Rother and lower Brede valleys are the together with an increase in particle size. The undifferentiated silty clays (unit 10) which invariably assemblage recorded at 1.85m O.D. is characterised by mantle the valley sides. Their stratigraphic position and the dominance of P. germanicum (720/,) and E. williamsoni lack of fossils (both pollen and foraminifera) suggests a (12%) with smaller numbers of A?nmonia tepida and colluvial origin. Similar but coarser deposits have been 14mmonia lirnnetes. The foraminiferal record suggests that reported from the lower Ouse \:alley by Jones ( 1971, deposition of these sediments initially occurred within an 1981). This colluvium does not appear to interdigitate intertidal marsh environment (at - 1.25m O.D.) with the other deposits and therefore pre-dates them. followed by an up-core increase in marine influence and The overlying valley fills can be subdivided into two environmental energy. Deposition of most of this major sedimentary facies or associations. The upper material probably took place within a sand/mud flat valleys are dominated by fluvial deposits which environment. Sedimentary and foraminiferal evidence interdigitate with the downstream sequences, occurring further suggest a slight increase in the marine influence prior to, contemporaneously with, and subsequent to, and environmental energy at 0.25m O.D. (suggesting a peat accumulation (see also Burrin 1988).However, as is transition to an intertidal sand flat environment), evident from the lithostratigraphy described above, the followed by a slight decrease in marine conditions and downstream valley fills are more variable and complex. environmental energy at 1.05m O.D. and 1.85m O.D., The deepest deposit of estuarine origin identified in possibly indicating a return to a mud flat environment. this study is the bluish grey sand (unit 3).This material is found over a wide area including Pett Level, the lower Brede Bridge Brede, the Rother Levels (at Blackwall Bridge), the Threesamples (-6.70mO.D., -6.10mO.D., -5.50m Royal Military Canal, and on the marshland along the O.D.) have been investigated from the pre-peat Stone Bridge to Snargate section. Texturally, it ranges in sediment, the blue clay (unit 4) at Brede Bridge composition from fine sand to coarse silts, and fines (borehole 53: see Fig. 1.13, TQ 830175). These upward and laterally into the bluish grey clay deposit assemblages are dominated by the hyposaline species 7. (Fig. 1.13) which appears to represent a fjcies change. injata and 3. macrescens. A few specimens of the The foraminiferal analyses from Pett Level, together euryhaline P. germanicum were also recorded. The low with the widespread occurrence of bivalve shells, species diversity suggests deposition occurred in a low indicates that this material was deposited under a energy intertidal marsh environment. marine influence. The general composition and An additional sample from the Brede valley was stratigraphic position of this unit suggests it can analysed from near Brede Waterworks (borehole 17, TQ probably be correlated with Green's (1968) Midley 8131 77). This material, a blue grey silty clay (unit 10) at Sand. This terminology has not been adopted however, -4.46m O.D., contained no foraminifera suggesting as Green used this name to describe both the near surface that deposition probably occurred in a freshwater sands above O.D. in the vicinity of Midley and the sands environment, beyond the limit of marine conditions. underlying the marshland sequence. It has been 24 Martyn Waller, Paul 3. Burrin and Andrew Marlow suggested (Green 1968; Eddison 1983a) that the sands at the marshland and therefore it is unknown whether, or Midley were deposited within a different depositionary to what extent, peat formation was diachronous. Dates environment, such as a sand spit or dune complex, and from what is likely to be the main peat bed of the they may post-date the bluish grey sand. Until the near marshland of c. 3000 B.P. and c. 3340 B.P. (Callow et al. surface deposits are more fully investigated the term 1964) are not incompatible with contemporaneous Midley Sand should therefore be restricted to the near organic accumulation occurring within both the surface sand outcrops in the vicinity of Midley. marshland and the valleys. However, it appears possible Overlying the bluish grey sand is usually the bluish that peat formation may have largely ceased in parts of grey clay (unit 4). The facies change from sand to clay these valleys (e.g. Brede Bridge) while occurring or suggests a change in the nature of the depositional continuing on the marshland. Green's (1968) correl- environment, which is confirmed by the presence in the ation of the two inch peat horizon (dated to 2050 f 90 clay of hyposaline foraminifera. It is not surprising B.P.) and the underlying 'clay with roots' deposit therefore to find that the bluish grey clay is thickest and (2740f 400 B.P.) at Scotney Court with the peat and most widespread in those lower valley sequences where lower blue clay of the marshland must be treated with there is a degree of protection. At Blackwall Bridge, to some scepticism given the differences in elevation (see the south of the Isle of Oxney, the blue sand penetrates Green 1968) and the large standard deviation associated furthest upstream, for here the lower Rother is with the older date. It should also be noted that the 'clay particularly exposed. Elsewhere the lower valleys are with roots' deposit cannot be dated by the root remains protected by outliers of the Hastings Beds Group (e.g. which presumably penetrated through the deposit. Old Place is sheltered by Winchelsea Hill and Small Dating the end of this phase of organic accumulation at Hythe by Chapel Bank). The bluish grey clay occurs different localities on the marshland remains one of the intermittently across the marshland as shown by Green most important outstanding tasks. The problems posed (1968) and by the sections from Pett Level and that by the only available index point (1830f 80 B.P.) have between Stone Bridge and Snargate. Its presence above already been stated (see pollen section). However, the the sand suggests a seaward extension of hyposaline difficulties experienced at Old Place (erosion of the peat conditions prior to organic accumulation. surface, compression and the possibility of an hiatus at One major lithostratigraphically continuous phase of the end of organic accumulation) are worth re- organic accumulation occurs over most of the area emphasising for they are also likely to affect other sites. considered here, as was suggested by Green (1968) for Evidence for erosional truncation of the peat surface the marshland. Additionally, an early Flandrian peat through sharp contacts and secondary peat deposition is occurs at Tilling Green, Rye, a thin intermittent deep widespread throughout the lower valleys and peat has been found (c. - 10m O.D.) in the lower Brede marshland. and isolated peats occur in the perimarine zone of the The inorganic sediments (units 6-9) which overlie the Brede and Pannel valleys which may have accumulated peat are the most variable element of the lithostrati- in response to locally high base levels. These additional graphy. However, the black and grey laminated sands, accumulations are the subject of further investigations. silts and clays (unit 6) found on Pett Level, the lower The deposits of the main peat bed appear to be Brede and the southern part ofthe Royal Military Canal autochthonous. Caution must, however, be exercised contain some readily identifiable features (colour, before extrapolating the type of plant communities stratification and shell fragments) through which recognised in the adjacent lower valleys during this correlation can be suggested. However, such character- phase to Romney Marsh in general. Well defined and istics were only found infrequently in the other sections. laterally consistent clay lenses have only been found Intensive investigations in the Brede valley have during these investigations within the peat on Pett revealed facies changes within this material with the clay Level, where foraminiferal evidence suggests they were content increasing upstream. Similar changes are also deposited in a hyposaline tidal marsh environment apparent in the overlying grey brown mottled sands, silts (Marlow 1984). Such intercalations become thinner and and clays (unit 8). This unit has therefore only been wedge out completely to the north, and have not been defined on the basis of colour from the underlying found in the lower Brede valley. material, which may largely be the result of oxidation The collection of material from the organic deposits of above the water table. Foraminiferal analyses shows the the marshland for radiocarbon dating during the 1960's uppermost inorganic sediments to have been deposited without adequate stratigraphic control is disappointing in low energy, estuarine environments at Pett Level and and seriously limits any attempt to construct a Old Place, which suggests continuity in the environment chronology for the area (see Table 1.3). The deep clastic ofdeposition at these sites. Despite the lithostratigraphic sediments beneath the peat appear to have been correlation of unit 8 along the length of the Brede valley, deposited prior to c. 6000 B.P. in the Brede, c. 5300 B.P. it is apparent that changes occur in the depositional on Pett Level (Welin et al. 1972) and c. 5000 B.P. (Welin environment. The grey brown silty clays at Brede Bridge et al. 197 1) at Blackwall Bridge (though only the Brede appear to have been deposited in a freshwater valley assay is from the lower contact of the peat). No environment (the pollen of open fen taxa predominate). radiometric evidence is yet available for the date of this Above Brede Bridge, the rise in floodplain altitude regressive overlap (terminology follows Tooley 1982) on indicates these sediments must have been deposited Flandrian Sedimentation and Palaeoenvironments 25 beyond any direct marine influence. which occurs at c. O.U. in three of the boreholes here The remaining major unit identified in the require further investigation in this respect. lithostratigraphy is the medium grey sand (unit 7) which Where this calcareous land-type abuts against a series occurs in the lower Brede, the Royal Military Canal and of old sea-walls between Appledore and Broomhill a the western end of the Stone Bridge to Snargate section. sharp contrast in relief is evident (Green 1968), with It is not found to the south of the Isle of Oxney at thick post-peat sediments on the seaward side. While Blackwall Bridge, but occurs at Small Hythe where it is such differences in height may largely have developed most clearly defined, filling a distinct bedrock channel because of such sedimentation (so that the sea walls some 125m wide (Fig. 1.15). This deposit can be traced would then provide an indication as to the age of this upstream to Newenden but at Bodiam only laminated material) such differences may also have been black, grey and brown sands and silts have been found accentuated by reclamation and drainage of the (see Burrin 1988). This may indicate the inland limit for marshland behind the walls resulting in peat shrinkage this unit which fines rapidly beyond Newenden. The or wastage. Whatever the age of these deposits, it is clear broad expanse of this medium sand in the Royal that they originated from the south, with the bulk of Military Canal section (Fig. 1.16) would appear to be sedimentation occurring on the western side of Walland where our boreholes run parallel to the course of these Marsh, thinning into the valleys and towards the sediments rather than orthogonal to it, as such deposits decalcified marshland to the east. Homan's ( 1938) were not located elsewhere south ofthe Isle ofOxney (see suggestion of a breach in the shinglr in the Camber- Fig. 1.15). Stratigraphic correlation with the other Broomhill area prior to the formation of the present Rye deposits is difficult because it was generally found from estuary, however, remains unproven. near the surface to the limit of penetration. Such Finally, it is interesting to compare the medium grey sediment post-dates the peat and also appears to overlie sands (unit 7), which appear to be associated with a the black laminated sediments along the Royal Military palaeochannel, with those described at the Rhee Wall. Canal. Foraminifera from a sample near Stone Bridge Here the deposits are essentially fine-grained with the suggests deposition occurred at the mouth of an estuary underlying peat intact suggesting a quieter depositional or in a near-shore region with a high environmental environment. Green's map (1968, 40) shows the course energy. The course of this material from Newenden, to of a natural waterway to be coincident with the artificial the channel at Small Hythe, the vicinity of Appledore, channel by Snargate. The lith~stratigraph~presented the eastern edge of the Isle ofOxney at Stone Bridge and here appears incompatible with the suggestion that a following the line of the Royal Military Canal south major river such as the Rother followed this route in the towards The Lock, is in close proximity with the present post-peat period. No significant channel has been cut routes of the Reading Sewer and Highknock Channel, into the peat and the sandy sediments to the north-east of which are believed to correspond to the course of the the Rhee Wall at Snargate have been shown by Green to Rother when it flowed north of the Isle of Oxney be part ofa creek-ridge system orientated towards Hythe between the 14th and 17th centuries (Rendel 1962). and to pre-date the Rhee Wall. The natural course as Similarly, the grey sand in the lower Brede valley may defined by Green (1968) therefore probably only coincide with the changes documented for this part of represents a major creek draining into an estuary at New the coast since the 13th century (Lovegrove 1953). Romney. Such a route for the Rother in the 12th century However, corroborative evidence for the age of this unit is also made unlikely by the probable existence of the is lacking and it should be noted that the grey sand may Walland Marsh (Rye) estuary prior to this date. This is well be associated and contemporaneous with the black not in conflict with that part of the Patent Roll records of laminated estuarine sands, silts and clays described 1257 (Green 1968; Eddison 198313) that suggests the above. Further research is required to resolve these Rhee Wall was used to connect the two tidal systems, issues. allowing the waters of the estuary at Appledore to be The various post-peat deposits described here can be channelled down the 'wall' during ebb flows, thereby broadly correlated with Green's (1968) 'land-type with helping to scour the New Romney estuary. common creek relics' which typifies the calcareous marshland over most ofwalland Marsh. The conflicting views of previous workers concerning the age of these Coastal Evolution sediments have already been noted. The new Several reviews of the data available for reconstructing radiocarbon evidence for this phase of sedimentation Flandrian sea levels on the South Coast have been made having been initiated after 1830 f80 B.P. (SRR. 2893) in recent years (Ackeroyd 1972; Shephard-Thorn 1975; at Old Place lends weight to the suggestion (Brooks Devoy 1982), although comparatively few detailed 1981) of a south-western estuary for the Rother prior to studies have yet been published. The rate of sea level rise the 13th century. As yet there is no unambiguous during the early Flandrian is considered by Devoy evidence for more than one depositional phase within (1982) to have been rapid, rising from c. - 25m O.D. at the post-peat sediments which might allow correlation 8500 B.P. to c. -6m O.D. at 6000 B.P. While the with the documented events of the late 13th century. relationship of the Tilling Green peat to sea level is The silty clays found above the peat on the northern part unclear, a rise in relative sea level in the Romney Marsh of the Royal Military Canal section and a thin peat area of a minimum of 17m can be suggested between 26 Martyn Waller, Paul J. Burrin and Andrew Marlow c. 9500 B.P. (Welin et al. 1974) and c. 6000 B.P. (Brede associated alluvial sequences becomes available, as our Bridge). Not surprisingly, therefore, most of the preliminary investigations have demonstrated through sediments identified as being deposited during this the possibility of a western exit for the Rother system period in the lower valleys and marshland are existing prior to the 13th century. minerogenic. Unfortunately, the palaeogeography of the area during the deposition of the lower blue grey sand and clay cannot be constructed until further studies The coastal sequences of Sussex reveal (if preserved) the sedimentary facies seaward of The comparison of the results of this study with other these deposits. investigations undertaken along the Sussex coast is The implications for coastal evolution of the regressive necessary if the recent debate concerning the relative overlap dated at Brede Bridge to c. 6000 B.P. are importance of local processes (e.g. the formation and unclear. Several alternative factors can be suggested to periodic breaching of barriers, Jennings and Smyth account for this. They include: the development of 1982a, 1982b) as opposed to regional factors (such as coastal barriers; a fall in relative sea level; the seaward relative changes in sea level, Burrin 1982) in the extension offreshwater and brackish facies as a result of a development of these sedimentary sequences is to be reduction in the rate of sea level recovery which appears resolved. to have taken place at about this time (see Devoy 1982), 'The earliest subsurface information for the lower or an increase in sediment supply, so that the upper part valleys of Sussex was collated in the geological memoirs of the bluish grey sand on the marsh may form part of a (Reid 1898; White 1924, 1926), while the inland limits of progradational beach system. While the apparent late Flandrian estuarine conditions were tentatively lessening of the marine influence prior to the regressive identified for the rivers Arun, Adur, Ouse and Cuckmere overlap is inconclusive, an assessment as to whether and from their floodplain long-profiles (Kirkaldy and Bull to what extent peat development was diachronous may 1940). At Amberley Wild Brooks (Arun valley) Godwin be useful in assessing the significance of these (1943) identified a derelict raised bog overlying a blue alternatives. It is clear, however, that the apparent clay which was presumed to be of estuarine origin. This arrival ofshingle on the coast by c. 5300 B.P. and barrier contact (at c. 1.5m O.D.) was subsequently dated to formation (Eddison 1983a, 1983~)cannot be inferred 2620f 110 B.P. (Godwin and Willis 1964) and recent from the accumulation of organic material alone. The investigations have shown that peat formation cont- earliest reliable evidence for the arrival of these coarse inued here beyond 1360f 80 B.P. (Waton 1982). littoral deposits is older than 3500 B.P. as indicated in However, the first detailed study of the lower valley the Tishy's Sewer Series (Tooley 1988). There is, as yet, alluvial deposits was that by Jones (197 1, 198 1) in the no conclusive evidence concerning the early stages in the Vale of the Brooks (Ouse valley), south of Lewes. Three development of the barrier system. The age, location, major lithostratigraphic units were recognised: fluvial composition and processes which led to barrier sands and gravels overlying bedrock or soliflucted Chalk formation have yet to be clearly defined. (Coombe Rock); bluish or greenish grey silty clays with At Brede Bridge a peat accumulation rate of 0.25cm interbedded peats; and finally, grey to black sands, silts per year can be inferred between c. 5970 and c. 3690 and clays with estuarine shells. Peats near the base of the B.P., assuming a constant growth rate and no silty clays have been dated to 6290f 180 B.P. and subsequent compaction or consolidation. Such a rapid 5677f 167 B.P., while the upper limit of this organic rate in a protected environment, where base levels are material (at - 2.3m O.D.) was dated to 3190f 125 B.P. likely to be controlled by sea level, suggests that the Accurate dating of this transgressive overlap may not dominant trend during this period continued to be one have been achieved however, as the surface of these fen of rising relative sea levels. The significance of the deposits appears to be truncated and rises to O.D. intercalated hyposaline clays at Pett Level is unclear. elsewhere. Jennings and Smyth ( 1982a) have suggested that similar More recent studies from the coastal sequences of deposits at nearby Combe Haven may be the result of Sussex have provided additional data. The investig- barrier breaching. Such a proposition cannot be assessed ations of Jennings and Smyth (1982a, 198213, 1985) at here by the investigation of a limited area near the Langney Point, Eastbourne have shown that freshwater extremity of these sediments, for relative sea-level conditions here were replaced by estuarine deposits at change could also account for the sedimentary sequences - 25.94m O.D., these in turn being overlain by a thin observed. peat (from -24.82m O.D. to - 24.70m O.D.). In contrast, the geographic limits of the transgressive Shephard-Thorn (1975) had earlier reported two dates overlap which forms Green's ( 1968) calcified marshland (95 10 f 75 B.P. from - 27.30m O.D. and 8760 f 50 B.P. over Walland Marsh can be adequately defined and from - 24.70m O.D.) from peat at Langney Point. appears to correlate with a major gap (c. 1800 B.P.?) in Jennings and Smyth (1985) obtained a further date of the shingle barrier, which was a product of changing 8770 f 50 B.P. from the transgressive overlap between coastal dynamics (Lewis 1932; Eddison 1983a). the thin peat and a subsequent bluish-grey estuarine Theories concerning the fashioning of the cuspate clay. These clays are replaced at - 14.20m O.D. by foreland and contemporary coastline will require marine sands which coarsen at c. -4m O.D. into the modification as new information on the nature of the shingle forming Crumbles Spit. Flandrian Sedimentation and Palaeoenuironments 27

The most extensive spread of recent coastal sediments exceptional: the absence of thick peat deposits here was after Romney and Walland Marshes is that of attributed to the relatively limited freshwater input by Willingdon and Pevensey levels. At Lottbridge Drove Jennings and Smyth ( 1985). Mid-Flandrian peats, (Willingdon Level) Jennings and Smyth (1982a) dated between c. 5400 B.P. and 3850 B.P., also occur in describe gravel overlying bedrock which is replaced by a the lower Thames valley (Devoy 1979) and possibly in bluish grey estuarine clay (from c. - 7.5m O.D. to the Solent (Nicholls and Clark 1986). Further - 1 .Om O.D.). These sediments are in turn overlain by a lithostratigraphic studies and dating of the contacts at thin peat dated between 3750f 40 B.P. and 3390f 40 the East Sussex sites are required in order to determine B.P. (Jennings and Smyth 1985) and an upper clay in the degree to which sedimentation here was influenced which a change from estuarine to freshwater conditions by local processes during the mid-Flandrian. Of was recognised. In western Pevensey levels a tripartite particular significance is the need to resolve the sequence consisting of a lower clay overlain by peat and alternative explanations which exist as to the formation an upper clay was recognised by Barnes (1974).Pottery of the intercalated clastic sediments which have been in the peat was tentatively dated to the medieval period. identified at several of these sites. A similar tripartite sequence was subsequently identified A further regional similarity in the lithostratigraphy in the eastern levels where the lower (bluish grey) of the Sussex coastal deposits is the occurrence of an claylpeat contact was dated to 3715 f 40 B.P., with peat upper estuarine unit above the main peat deposits in the formation continuing beyond 480f 50 B.P. at one site Ouse (Jones 197 1, 198l), Combe Haven (Jennings and (Moffat 1984). Lithostratigraphic investigations Smyth 1982a), the western side of Romney Marsh and (Smyth 1982; Jennings and Smyth 1982a) have also associated river valleys, and the thin peat on Willingdon taken place further along the coast at Combe Haven, a Level (Jennings and Smyth 1985). The available small valley between Bexhill and Hastings. Here, gravel radiocarbon evidence for the initiation of this phase (c. is overlain by essentially blue estuarine clays with 3400 B.P. at Willingdon Level, c. 3200 B.P. in the Ouse intercalated peats (below c. - 6m O.D.). The largely and c. 1800 B.P. in the Brede) suggests that these deposits organic unit which follows is in turn superseded by an may not be contemporaneous. Such incursions might be orange-stained clay which appears to have deposited the result of barrier breaching, as appears likely in the under estuarine conditions in the lower reaches of the case of the Brede. Barriers have played a significant role valley. in coastal development in the historic period and the It is evident from this brief summary that few of these existence of shingle deposits at Broomhill on Romney coastal alluvial sequences have yet been studied in detail Marsh at c. 3500 B.P. (Tooley 1988) suggests the and the results published. Hence, it is premature to formation of a barrier system by this period. The dating attempt to correlate the sequences from the Romney of the transgressive overlaps in these valleys is, however, Marsh area with these other sites. Local processes can problematic and the formation of the upper inorganic only be separated from regional events if comparisons sediments by such a process does not necessarily imply are made from sediments deposited contemporaneously they were deposited diachronously. Other factors, such with due regard to variations in physiography and facies as variations in the supply of sediment by longshore drift changes. and storm surges, may also have had an impact which Data concerning the early Flandrian evolution of the can be detected along the coast. Again, further Sussex coast is very sparse. Peats of this age occur at investigations are required to elucidate fully the Tilling Green, Rye and Langney Point, Eastbourne, processes and reponses involved. though the relationship of these sediments to sea level and coastline configuration remains unclear. The depth of these deposits and the liklihood of the compaction, erosion and reworking of sediments of this age hinder palaeogeographic reconstructions of this period. While Conclusions the absence of data makes the assessment of the It is evident from these discussions that further contribution of local and regional processes difficult investigations are required to resolve a number of during this period, the change in sea level from c. 10000 significant issues. These include: B.P. to 6000 B.P. suggested by the data currently 1) The establishment of a reliable chronology for the available (Devoy 1982) is so great that it must have had marsh by radiocarbon dating the major peat unit. This a pronounced regional effect. should only proceed, however, after extensive lithostrati- The influence of a regional process, with a reduction graphic and biostratigraphic studies have established in the rate of sea level rise, or a fall in relative sea level, reliable transitional zones. also appears to be apparent in the mid-Flandrian. The lower Ouse, Brede and Rother valleys, and Combe 2) The delimitation of the sedimentary units identified Haven all contain thick organic deposits of mid- during the course of these investigations. Only then can Flandrian age. Although they are located in topographi- the palaeogeography of the area be reliably re- cally confined situations, a lessening of the marine constructed for different periods during the Flandrian. influence appears to have occurred prior to the elm Of importance here is the relationship between the blue decline at these locations. Willingdon Level appears sand and the arenaceous deposits in the Midley area. 28 Martyn Waller, Paul J. Burrin and Andrew Marlow

3) Further investigations are required into the nature evolution of this area during the Flandrian period. The and origins of the Rhee Wall and Sedbrook Sewer in application of an inter-disciplinary framework as order to test the various hypotheses which have been put employed here is essential if the problems identified forward concerning the previous courses of the Rother. above are to be resolved. 4) Reassessment of the evolution of the shingle barrier. This will require the delimitation of the sedimentary units as suggested above for it is only then that the dynamics of the barrier system can be reconstructed with Acknowledgements due regard to the importance of such factors as past sea The authors would like to express their sincere thanks to levels, storm surges and sediment budgets. the following: the site investigation unit of East Sussex County Council and Dr. E. R. Shephard-Thorn of the 5) Further detailed studies of other coastal alluvial British Geological Survey for borehole data; Dr. D. D. sequences in this area are also required in order to Harkness and NERC for the radiocarbon dates; Dr. R. understand the regional processes through which these H. Bryant, Dr. B. D'Olier, Dr. M. J. Tooley and Dr. J. deposits formed during the Flandrian. Whittaker for their helpful comments on an earlier draft This paper is a preliminary attempt to synthesize the of the manuscript; Mr. S. Brown, Mr. D. Eccles, Mr. P. results of research in the previously neglected lower Hissey, Mr. A. Thompson and Mr. S. Wood for their valleys of the Romney Marsh area. We are continuing assistance in the field; and finally to David Lawes for his the investigations described here with further emphasis endless patience in drawing the diagrams. 'The research on the sequences of Romney Marsh. It is clear that was partly funded by grants from the L.S.B. Leakey considerably more data are required before further Trust and Goldsmiths' College which are gratefully theories can usefully be constructed concerning the acknowledged.

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sedimentation in the Devoy estuary (Wales). Geol. Journ. 6, Reid, C. 1898: The geology of the countcF around Eastbourne. (Mcm. Geol. 2 17-256. Surv.). Homan, W. M. 1938: The marshes between Hythe and Pett. Sussr.~ Rendel, W. V. 1962: Changes in the course ofthe Rother. Arc. Cant. 77, Arch. Cull. 79, 199-223. 63-76.

Huntley, B. and Birks, H. J. B. 1983: An atlas ofpast andpresentpollen maps Shephard-Thorn, E. R. 1975: The Quaternary of the Weald - a for Europe: 0-13000years ago. (Cambridge). review. Proc. Geol. Ass. 86, 537-547. Hutchinson, J. N., Poole, C., Lambert, N. and Broomhead, E. N. 1985: Shephard-Thorn, E. R., Smart, J. G. O., Bisson, G. and Edmonds, E. Combined archaeological and geotechnical investigations of the A. 1966: Geology of the country around Tenterden. (Mem. geol. Surv.). Roman fort at Lympne, Kent. Britannia 16, 209-236. Smart,J. G. O., Bisson, G. and Worssam, B. C. 1966: Thegeology of the Jennings, S. 1985: Late Ouaternary enriironmental change at Eastbourne, East country around Canterbucv and Folkestone. (Mem. geol. Surv.). Sussex. (Unpublished Ph.D. thesis, Polytechnic ofNorth London). Smith, A. G. and Pilcher, J. R. 1973: Radiocarbon dates and Jennings, S. and Smyth, C. 1982a: A preliminary interpretation of vegetational history of the British Isles. 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Fig. 2.1 The Rather vallty showing location of cross-sections and former Wealden iron-working sites.

FRESHWATER

WEALD CLAY

WADHURST CLAY ASHDOWN BEDS PURBECK BEDS

Fig. 2.2 Generalised geology of the Rother valley (modijied from the British Geological Suruq).